The present invention relates to specula, and in particular to specula of the eyelid retractor type for use in ocular surgery or the like wherein the eyelids must be drawn back or open to allow access to the eyeball.
Conventional eyelid retractors are typically characterized by screw locking devices, knobs, and/or pointed ends. These screw locking devices, knobs, and pointed ends tend to snag or catch suturing material normally used in eye surgery. Such suturing material is very fine and is thus often broken or caught increasing the time and labor of such surgery. Even if the suturing material is not caught, sharp and/or pointed portions of such eye retractors present a constant threat of suture breakage which in turn slows surgery as doctors must be extra careful to avoid such breakage.
The conventional eyelid retractors often utilize spring mechanisms to bias apart the eyelids. Such spring mechanisms often tend to produce a post-operative effect known as ptosis or drooping of the eyelid. Ptosis is normally the result of excessive pressure being placed on the eyelid muscles by the eyelid retractor, especially a spring portion thereof, during surgery. Conventional spring mechanisms are believed to cause the ptosis sincce they are often uncontrolled or when controlled by a locking device, there is normally some difficulty in properly adjusting the associated locking device to apply just the proper separative pressure.
In addition many conventional eyelid retractors are not self supporting. Such retractors often extend horizontally from the eye and thus require some support to sustain such a horizontal attitude. Even those retractors which are preformed to somewhat follow the contour of the face, are not adjustable for variances in face structure and therefore often transmit a torque to the eyelids, which torque is also believed to cause ptosis.
During ocular surgery or the like, it is often necessary to utilize extensive equipment which must be placed relatively close to the eye and/or face area surrounding the eye. Typical of such equipment is the Kelman Phaco Emulsification Unit used in cataract removal. As conventional eye retractors often have portions extending above the face area surrounding the eye, a surgeon must either use alternative and sometimes less desirable equipment or remove the eyelid retractor such that the eyelids are then in the operative way of the surgeon.
Conventional eyelid retractors are typically only slightly, if at all, adjustable to the face and/or eye of the patient. Such retractors infrequently come in varying sizes. The most standard adjustment is in control of the spread or distance between the eyelids, which distance is normally produced by the urging of a hairpin, coil, or the like type of spring. The age, sex, race, and general facial structure, especially the bone structure, of each patient present substantially different features to a surgeon in every operation, which features can not generally be conformed to by conventional eyelid retractors. Preferably a different eyelid retractor should be utilized for each patient which retractor conforms to the particular feature of that patient.
In addition conventional eyelid retractors often have moving parts, must be manufactured to fine tolerances and must be constructed so as to retain such tolerances, all of which tend to increase the cost of such retractors. Thus, it is desirable to produce a retractor which is relatively inexpensive compared to conventional retractors and thereby reduce operating expense.